function showitemscategory(items) {
   document.getElementById("categories").style.display="none";
   document.getElementById(items).style.display="inline";
}
function noshowitemscategory(items) {
   document.getElementById("categories").style.display="inline";
   document.getElementById(items).style.display="none";
}
function itemquantity(item,cant) {
   var num = parseInt(document.getElementById(item).value);
   if(num>1){
      if(cant=="less"){document.getElementById(item).value=num-1;}
   }
   if(cant=="more"){document.getElementById(item).value=num+1;}
}
function addChar(character)
{
   if(document.getElementById("amount_tendered").value == null ||document.getElementById("amount_tendered").value == "0"){document.getElementById("amount_tendered").value = character;}
   else{document.getElementById("amount_tendered").value += character;}
}
function vaciar(character)
{
   document.getElementById("amount_tendered").value = character;
}